Pardon me, but if the air is cooler that means the plant itself would have to be absorbing the heat from the air, which in turn would make the plant warmer, is that correct?
It's been a while since my thermodynamics courses in school, but just like an air conditioner the thermal energy has to go somewhere, so if a plant is warming the air around it then it has to be shedding that heat FROM something, and if it is cooling the air then it the opposite would also be true, wouldn't it?
It just seems that what this guy just said is backwards to me is all.
Abathar -the important effect here has nothing to do with the plant directly cooling in any way. Paul51 had a good synopsis in his post#7. Ernest_at_the_Beach post#24 has a good piece of the puzzle there, too. Since there are other posters who may like to see this, I will ping them here, too ... Let me go back to first principles:
Everyone agrees that doubling CO2 by itself will not induce warming of more than about 1C. The important process that has been postulated by the “warmers” is that an increase of Carbon Dioxide will induce the “positive feedback” of increasing water vapor in the atmosphere, and this in turn causes an amplified “greenhouse effect” as alloysteel points out. The warmers have incorporated no significant negative feedbacks in their hypothesis.
This research turns that paradigm completely upside down since it shows the plants in Florida have been adapting to the increased CO2 by lowering the number of stomata they carry - thus lowering the amount of water vapor they return to the atmosphere. By the way, there is a picture I am going to bring into my next post - so take a look at it - The change of stomata was very dramatic, not minor.
If this is shown to be a worldwide effect - quite likely in my estimation - it will explain the lowering humidity in the upper atmosphere as CO2 has been increasing over the last half century, as shown in the graph I included in my first comment. In this way, plants have been providing a negative feedback with increasing CO2 instead of the strictly positive feedback that has been incorporated in the computer models and other AGW theory.
My eyeballing of the data makes it appear that the total effect of increasing CO2 is likely to be nearly neutral with respect to temperatures... How it will affect rainfall and other aspects of climate long term is less clear. Since there are two major types of plants using different types of photosynthesis (”C3” vs “C4”), increased CO2 and lower humidity may favor a re-balancing of the vegetative types, and I have no good handle on how that would play out.
In any event, this research showing a strong negative feedback on humidity, and thus temperature, with increased CO2 due to the way plants adapt, completely turns the whole field upside down. Honest computer models will have to attempt to incorporate the way plants change over time and the way they regulate humidity in the atmosphere.
This research represents a serious groundbreaking development in the field.